Low vision in persons aged 50 and above in the onchocercal endemic communities of Anambra State, Nigeria.

OBJECTIVE

To determine the prevalence and causes of low vision among persons aged 50 and above in the onchocercal endemic rural areas of Anambra State, Nigeria.

MATERIALS AND

METHODS

Normal residents of three onchocercal rural villages in 3 local government areas of Anambra State, Nigeria, selected through simple random sampling, were examined using interviewer-administered structured questionnaire. Eye examination included visual acuity test, refraction, tonometry, color vision test and direct ophthalmoscopy. Skin-snips were examined for onchocercal microfilaria.

RESULTS

Four hundred and seventy-two persons aged 50 years and above were examined, out of which 8.6% were bilaterally blind; 11.9% were monocularly blind and 23.7% had visual impairment. Cataract caused blindness in nearly two-third of the cases. Other causes of low vision include age-related macular degeneration, glaucoma, onchocerciasis and refractive errors. Of the 56 subjects blinded by cataract in at least one eye, only 16 (28.6%) had undergone cataract surgery. But none had intra-ocular lens implant. Only 2 of these 16 subjects had aphakic eyeglasses.

CONCLUSIONS

Blindness rate among the population studied is 6 times the rate in similar aged-matched population in developed countries. Most of the bilaterally blind will have vision restored through cataract surgery. Cataract extraction with intra-ocular lens implant is recommended for better visual rehabilitation.